Signaling through submarine and like cables.



No. 801,800. PATENTED OCT. 10, 1905. 0. J. LODGE & A. MUIRHEAD.

SIGNALING THROUGH SUBMARINE AND LIKE CABLES. APPLICATION FILED 11.25, 1905.

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f ou'mr Jlod c No. 801,800. PATENTED O0T.10,1905. O. J. LODGE & A. MUIRHEAD.

SIGNALING THROUGH SUBMARINE AND LIKE CABLES.

APPLICATION FILED $1 11.25, 1905.

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UNITED STATES PATENT OFFICE.

OLIVER JOSEPH LODGE, OF BIRMINGHAM, AND ALEXANDER MUIRHEAD, OF LONDON, ENGLAND.

SIGNALING THROUGH SUBIVIARINE AND LIKE CABLES.

Specification of Letters Patent.

Patented Oct. 10, 1905.

Original application filed October 3, 1904, Serial No. 227,082. Divided and this application filed April 25, 1905. Serial No. 267,377.

To a. 1071/0710 it Htay concern:

Be it known that we, OLIVER J osEPn LODGE, knight, F. R. S., principal of the University of Birmingham, residing at Mariemont, Edgbaston, in the city of Birmingham, and ALEX- ANDER MUIRHEAD, D. So, electrical engineer, residing at 12 Oarteret street, IVestminster, London, S. L, England, subjects of the King of Great Britain and Ireland,'have invented certain new and useful Improvements inand Relating to Signaling Through Submarine and Like Cables, of which the following is a specification.

Our invention relates to improvements in the transmission of signals through submarine and like cables, and has for its object to increase the rate of signaling through such cables.

In order to increase the rate of signaling, it is important to employ higher electromotive forces than have hitherto been used; but the application of such higher electromotivc forces has been hitherto avoided on account of the risk of damaging the cables.

Now our invention is directed to the utili- Zation of electromotive forces of fair magnitude, but of so short a duration that no dangerous effect can be produced in the deep-sea portion of the cable by reason of inadvertent continuous application of the high electromotive force.

Our invention is also directed to the production of suitable curbing of the signals, so as to enable the high rates of working to be maintained.

Our invention consists in producing the current surges required for signaling and for curbing by means of the oscillatory discharge of a condenser in a local circuit of suitable inductance.

Our invention further consists in a device comprising a source of current or arrangement of one or more circuits containing an inductance and a capacity in series adapted to produce inductive current surges under the action of an operating-key which is so timed in its movements in relation to the period of the surges as to give signaling surge in one direction and a curbing surge in the opposite direction following (owing to the oscillatory character of the circuit) quickly behind the signaling surge, a number of pulses only being effective and the remainder being cut off.

We employ a condenser and inductance in series in a local circuit suitably proportioned in relation to one another as to give an oscillatory discharge, and so produce the current surges required for sending and curbing according to our invention, the current surges being conveyed to the cable either by reason of a part of said circuit being itself in series between the cable and earth or inducing an oscillation in a conductor which is in series between the cable and earth. The surge used for signaling is sent on the depression of the key to discharge the condenser, the curbing being effected by the recoil surge in the opposite direction, and the signaling-key may be so timed that two pulses only are effective, the remainder being cut oti'.

It is important that the automatic keys should be operated by a suitable impact, and we provide two operating-keys, one of which sends a positive pulse first into the cable, giving at the receiving end a deflection to the right, while the other sends a negative pulse first and deflects the receiving instrument to the left, and both keys can be worked either automatically or by hand, as desired.

It will be obvious that we may employ any existing duplex device instead of a simple cable as the recipient of the pulses. For the purposes of receiving the signals at the other end any of the present methods may be used.

Referring to the accompanying drawings, which represent diagrammatically various ways of carrying our invention into eli'ect, Figure 1 shows a form of our invention in which two batteries and two condensers are used. Fig. 2 shows a similar arrangement working duplex. Fig. 3 shows a modification in which the surges used in the cable are inductively derived. Fig. 4: shows a modification of the form shown in Fig. 1, while Fig. 5 is a diagrammatic view showing a method in which one condenser and one battery only are employed.

In Fig. 1 the cable a is connected to earth through a self-induction coil 6. Two condensers 0 d with charging-batteries (1 y" are connected with the self-induction coil, through which either condenser can be discharged by operating one or other of the keys 7 It. It will be seen that the two batteries are so arranged that the condensers will be oppositely charged and that the battery can never send a direct current into the cable.

The inductance and capacity in the closed condenser-circuits are such that an oscillatory discharge takes place, the overflow into the cable of the first surge in one direction giving the signal, and the overflow of the opposite surge, which completes the first oscillation of the discharge, giving the curb.

We have found that if the product of the total capacity and total resistance of the cable is four seconds the best values of the condensers, coil, and batteries for high -speed working are as follows: capacity of condensers, forty microfarads each; inductance and resistance of coil, ten henries and one hundred ohms, respectively; electromotive force of batteries, one hundred volts each. It will be seen that in this arrangement, as in all the variations of our invention, the succession of signaling and curbing pulses takes place without a second contact of the key. The receiving instrument may be any one of those at present in use, and a condenser may be used in the receiving-circuit in the ordinary manner.

We may arrange that the signaling-key is actuated by an automatic transmitter, and in this case the key will be preferably so timed that the closed condenser-circuit is broken at the end of the first complete oscillation of the discharge. The return of the keys against their stops puts the batteries again in connection With the condensers for recharging. The amount of curbing may be regulated by a resistance is in series with the coil 6. Also the application of the cable to the closed condensercircuit has the effect of damping the oscillations very rapidly, the extent of such damping depending on the capacities and inductances of the cable and condenser-circuits. The curbing surge, therefore, is not so strong as the signaling surge and may be varied in strength by altering the capacity of the condenser, and adjustment can thus be obtained so that the siphon-recorder may return definitely to the zero-line after each signal. Also we may arrange the capacities of the cable and condenser-circuits so that only the first oscillations are effective, the damping being sufficient to render following oscillations inappreciable.

Fig. 2 is a diagram showing the application of an automatic transmitter in working the keys of the condenser-circuits electromagnetically, the arrangements of the condensercircuits and the cable being exactly as shown in Fig. 1 and the connection to the cable being arranged for duplex working. The keys 9 it are operated by hammer-levers a j, which are actuated by electromagnets Z m, operated by an automatic transmitter a or by handkeys. For duplex working a rheostat R is connected to a common point of the two condenser-circuits and to two separate series of coils 0 10 of suitable inductance wound together on the same axis, the ends of these coils being connected, respectively,to the ends of the cable a and artificial line q. The receiving-condenser 1' and siphon-recorder s are' placed in series between the junction of the cable and artificial line, respectively, with the-coils 0 p.

Fig. 3 shows a modification similar to those above described, except that the coil 6 in the oscillating circuit is made to act inductively upon a coil Z, placed in series between the cable and earth, and is not in direct connection with the cable.

In the modifications shown in Fig. 1 the signal is sent and curbed, as in Figs. 1 and 2, by the oscillatory discharge of the condensers 0 d through the coil 7), which is in series between the cable a and earth. A supplementary coil 6 is connected to the cable and between the batteries 0 f and has the efi'ect of giving a modified curbing action. The resistance is, as before, controls the curb, and a supplementary control is given by the coil 6.

Fig. 5 shows a modification of our invention, in which only one condenser 1 and battery 2 are employed. The two keys 3 4 correspond'to the two keys 9 h in' the preceding figures, and an extra lever 5 is added for the purpose of disconnecting the single battery 2 from the single condenser 1 immediately before the latter is discharged on the depression of one or other of the keys 3 4 during signaling. In signaling with this arrangement the lever 5 is first depressed and then one or other of the keys 3 4, discharging the condenser 1 through the circuit E& 3 I; E, the first surge of the discharge being the signaling surge and the return surge the curbing surge.

We may apply any of the above-described methods of signaling to any of theordinary arrangements for duplex telegraphy, and we have found that the sinuous curbing obtained by utilizing the oscillatory discharge produced by a suitable capacity and inductance in series makes balancing in duplex telegraphy more easy. In all the arrangements we have described the keys shown in the figures in the condenser-circuits are diagrammatic, and we prefer in every case to actuate these keys by means of electromagnets, which may either be operated by an automatic transmitter or by hand.

Having now described our invention, what we claim as new, and desire to secure by Letters Patent, is 1. Means for transmitting signals through submarine and like cables, comprising in combination, a local circuit, a condenser and inductance in series in said local circuit, means for closing said local circuit to discharge the condenser, the capacity and inductance in said local circuit being such that the discharge is oscillatory, and a cable adapted to receive electric impulses due to said discharge.

2. Means for transmitting signals through submarine and like cables, comprising in combination, a local circuit, a condenser and inductance in series in said local circuit, a contact-lever adapted to be operated to close said local circuit and so discharge the condenser, the capacity and inductance in said local circuit being such that the discharge is oscillatory, a connection to the cable, an earth connection said inductance being in series between the cable and earth, as and for the purposes described.

3. Means for transmitting signals through submarine and like cables, comprising in combination, a local circuit, a condenser and inductance in series in said local circuit, a contact-lever adapted to be operated to close said local circuit and so discharge the condenser, the capacity and inductance in said local circuit being such that the discharge is oscillatory, a connection to the cable arranged for duplex working, an earth connection, said inductance being in series between the cable and earth, as and for the purposes described.

4. Means for transmitting signals through submarine and like cables, comprising in combination, a local circuit, a condenser and inductance in series in said local circuit, a contact-lever adapted to be operated to close said local circuit and so discharge the condenser, an electromagnet adapted to operate said contactlever, the capacity and inductance in said local circuit being such that the discharge is oscillatory, a connection to the cable, an earth connection, said inductance be ing in series between the cable and earth, as and for the purposes described.

5. Means for transmitting signals through submarine and like cables, comprising in combination, a local circuit, a condenser and inductance in series in said local circuit, a contact-lever adapted to be operated to close said local circuit and so discharge the condenser, an electromagnet adapted to operate said contact-lever, an automatic transmitter adapted to actuate said electromagnet, the capacity and inductance in said local circuit being such that the discharge is oscillatory, a connection to the cable, an earth connection, said inductance being in series between the cable and earth, as and for the purposes described.

6. Means for transmitting signals through submarine and like cables, comprising in combination, a local circuit, a condenser and inductance in series in said local circuit, a contact-lever adapted to be operated to close said local circuit and so discharge the condenser, the capacity and inductance in said local circuit being such that the discharge is oscillatory, a connection to the cable, an earth connection, said inductance being in series between the cable and earth, a resistance in series between said inductance and earth, as and for the purposes described.

7. Means for transmitting signals through submarine and like cables, comprising in combination, an inductance in series between the cable and earth, two local circuits of which said inductance forms a part, two condensers arranged one in each of said local circuits,

contact-levers adapted to discharge said condensers through said local circuits, the inductance and capacity in said local circuits being such that the discharge is oscillatory, as and for the purposes described.

8. Means for transmitting signals through submarine and like cables, comprising in combination, an inductance in series between the cable and earth, two local circuits of which said inductance forms a part, two condensers arranged one in cachof said local circuits, two batteries oppositely disposed and normally having their poles connected to the terminals of said condensers, contact-levers adapted to be operated to disconnect said batteries and to discharge said condensers through said 10- cal circuits, the inductance and capacity in said local circuits being such that the discharge is oscillatory, as and for the purpose described.

9. Means for transmitting signals through submarine and like cables, comprising in combination, a cable arranged for duplex working, an inductance in series between the cable and earth, two local circuits of which said inductance forms a part, two condensers arranged one in each of said local circuits, contact-levers adapted to discharge said condensers through said local circuits, the inductance and capacity in said local circuits being such that the discharge is oscillatory, as and for the purposes described.

10. Means for transmitting signals through submarine and like cables, comprisingin combination, an inductance in series between the cable and earth, two local circuits of which said inductance forms a part, two condensers arranged one in each of said local circuits, two batteries oppositely disposed and normally having their poles connected to the terminals of said condensers, contact-levers adapted to be operated to disconnect said batteries and to discharge said condensers through said local circuits, electromagnets adapted to operate said contact-levers, the inductance and capacity in said local circuits being such that the discharge is oscillatory, as and for the purpose described.

11. Means for transmitting signals through submarine and like cables, comprising in combination, an inductance in series between the cable and earth, two local circuits of which said inductance forms a part, two condensers arranged one in each of said local circuits, two batteries oppositely disposed and normally having their poles connected to the terminals of said condensers, contact-levers adapted to be operated to disconnect said batteries and to discharge said condensers through said local circuits, electromagnets adapted to operate said contact-levers, an automatic transmitter adapted to actuate said electromagnets, the induetance and capacity in said local circuits being such that the discharge is oscillatory, as and for the purpose described.

v 12; Means for transmitting signals through i submarine and like cables, comprising in combination, an inductance in series between the cable and earth, a resistance in series between said inductance and earth, two local circuits of which said inductance forms a part, two condensers arranged one in each ofsaid local circuits, contact-levers adapted to discharge said condensers through said local circuits, the inductance and capacity in said local circuits being such that the discharge is oscillatory, as and for the purposes described.

In testimony whereof we have signed our names to thls specification 1n the presence of the subscribing Witnesses.

OLIVER JOSEPH LODGE. ALEXANDER MUIRHEAD.

Witnesses as to Oliver Joseph Lodge:

EDWARD MARKS, JOHN MORGAN.

l/Vitnesses as to Alexander Muirhead:

BERTRAM H, MATTHEWS, GEORGE I. BRIDGES. 

